Transposing errors when importing MusicXML file

I have imported a full orchestral score in MusicXML - which is in Bb/G minor.
In the full score display Bb transposing instruments are in Ab/F minor and Horns in F are in Eb.
When I switch to individual scores - the Bb instruments and the Horn parts now all appear in Bb!
I am new to Dorico, but as I understand it full score parts should all appear at sounded pitch, and when a switch is made to a transposing instrument’s individual part, only then is the transposed key displayed.
So something is working in the opposite direction - all transposing instruments should appear in Bb in the full score - but Bb instruments have moved down a tone instead of up (Bb down to Ab not up to C) - horns should be in F (not Eb) - but again this should only be shown in individual parts. I have tried all kinds of approaches but am stuck, and am thinking that this has to be some aspect of the MusicXML file. The crucial thing is how I can get round this!

Welcome to the forum, chris62desford. Where did the MusicXML file come from? MusicXML files are always (or at least always should be) encoded in transposing pitch, so unless the original document in Finale or Sibelius or whatever application the MusicXML file was exported from was completely messed up in terms of transposition, you should be OK in Dorico as well. You can switch the full score to be in transposed pitch from the Edit menu.

If you really can’t figure out what to do, you can zip up and attach the troublesome project here, and we can take a look.

I guess that whoever created the score didn’t understand how transposition is supposed to work and messed about until they got something that “looked right” with the transposing and non-transposing switches set the wrong way round. So they really had clarinets in D and horns in some other weird key not F.

Switch to a non-transposing score view in Dorico and transpose the notes to give the correct sounding pitches. You may have to delete some weird key signatures as well. Then in Setup Mode change the instruments to the correct ones and the transposed score and parts should be correct.

Dear Daniel and Rob - thanks for your help and suggestions. (apologies for delay in responding, but I was waiting for an email notification that my post had been approved) The MusicXML score was downloaded from MuseScore - although I think I have had similar problems with MusicXML scores from PhotoScore. I finally edited the MusicXML file and removed all the tags and their contents. I then imported the score again - with the name of the transposing instrument displayed in Dorico. I then “changed instrument” (effectively to the same instrument!) and everything worked OK. As you say, the score must have been messed up to start with (plainly reversing “sounding” and “written” pitch!) Anyway, thanks again for your helpful suggestions.